1. Field
The disclosed concept relates generally to electrical systems and, more particularly, to aerospace electrical systems, such as, for example, power distribution units. The disclosed concept also relates to matrix assemblies for aerospace electrical systems.
2. Background Information
Aircraft or aerospace electrical systems generate, regulate and/or distribute power throughout an aircraft.
Aerospace power distribution units (PDUs), for example, generally include an enclosure, a number of input and output connectors, internal electrical bussing, electrical conductors, a number of electrical switching apparatus, such as contactors, circuit breakers, relays and the like and/or fuses. More specifically, in aircraft or aerospace electrical systems relatively small circuit breakers, commonly referred to as subminiature or aircraft circuit breakers, are often used to protect electrical circuitry from damage due to an overcurrent condition, such as an overload condition or a relatively high level short circuit or fault condition. Aircraft circuit breakers also often serve as switches for turning equipment on and off, and are grouped together as part of a circuit protection module with the circuit breakers/switches being accessible on an outer panel of the enclosure, within the aircraft.
Within the enclosure, a backplane made of melamine or a suitable thermoset compound is typically employed to meet dielectric insulation requirements and suitably separate and isolate the electrical components. However, significant heat is generated in aircraft electrical systems, which increases resistivity and adversely affects system performance. For example, for a contactor with a voltage drop of 0.105 V for two contact points and a load current of 400 A, the total heat generation is 42 W or 21 W per contact. The electromagnetic coil of the contactor is also a source of heat generation. Likewise, fuses generate heat. For example, for a fuse with a voltage drop of 0.1 V and a load current of 260 A, the volumetric heat generation is 26 W. While the melamine or thermoset material of the backplane generally serves well as an effective electrical insulator, it is thermally insulative and, therefore, prevents good heat transfer to free air or the aircraft structure.
There is room for improvement in aerospace electrical systems and matrix assemblies therefor.